Mendeleev place hydrogen at top of group 1 in his version of the periodic table. The modern periodic table does not show hydrogen in group 1 state one similarity between hydrogen and the elements in group one

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.

it's c (engineer's do their work with mechanical stuff not on any living being)